Headgear

ABSTRACT

A headgear for securing and positioning a mask suitable for the treatment of sleep disordered breathing is constructed from a composite including polyurethane foam. It includes a back portion with upper and lower straps connected to the back portion. The straps have relatively narrow strap ends the lower straps are displaced downward with respect to the back portion. A quick release mechanism near the front of the face attaches the headgear to the mask. Additional components can be attached to the straps to alter their elasticity and stiffness.

CROSS-REFERENCES TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 10/433,779, filedJun. 6, 2003, allowed, which is a national phase of InternationalApplication No. PCT/AU01/01607, filed Dec. 12, 2001, which claims thebenefit of U.S. Provisional Application No. 60/254,537, filed Dec. 12,2000, each incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to headgear for use with a mask suitable for thedelivery of non-invasive positive pressure ventilation and for nasalCPAP treatment of sleep disordered breathing conditions such asobstructive sleep apnea.

2. Description of Related Art

Obstructive Sleep Apnea (OSA) is a disease characterised by excessivedaytime sleepiness, loud snoring and daytime irritability. Other effectsof OSA can include depression, high blood pressure, serious heartconditions, sexual problems, memory lapses, intellectual deteriorationand morning headaches.

The treatment of OSA by the application of nasal Continuous PositiveAirway Pressure (CPAP) was invented by Sullivan and is described in U.S.Pat. No. 4,944,310 (Sullivan, assigned to ResMed Limited). The techniqueinvolves the application of a flow of pressurised breathable gas(typically room air) to either the nose or nose and mouth of a patientwhile they sleep. The technique is said to “splint” open the airways.Typical treatment pressures are in the range of 3 to 20 cmH2O. Flows areup to approximately 200 L/min. The flow of pressurised air is producedby a blower and delivered to the patient via a patient interface. Theblower and patient interface are joined by a conduit. Whilst there areother techniques for the treatment of OSA, such as surgery, the use ofCPAP has become the “gold” standard.

For a particular patient, the pressure which is needed to maintain openairways can vary throughout the night and vary on different nights. U.S.Pat. No. 5,245,995 (Sullivan and Lynch, assigned to ResMed Limited)describes a method and device for varying the pressure in accordancewith indications. For example, if the patient starts to snore, thepressure automatically increases, whilst in the absence of snoring, thepressure automatically decreases.

Non-Invasive Positive Pressure Ventilation (NIPPV) is another form oftreatment for breathing disorders. In its most basic form, it involves arelatively higher pressure of gas being provided in the patient maskduring the inspiratory phase of respiration and a relatively lowerpressure or atmospheric pressure being provided in the patient maskduring the expiratory phase of respiration. Typical treatment pressuresare in the range of 3 to 30 cmH, 0.

In other NIPPV modes, the pressure can be made to vary in a complexmanner throughout the respiratory cycle. For example, the pressure atthe mask during inspiration or expiration can be varied through theperiod of treatment, as disclosed in international PCT patentapplication no. PCT/AU97/00631 (Berthon-Jones, assigned to ResMedLimited).

In this specification, any reference to CPAP is to be understood asembracing all of the above-described forms of ventilatory treatment orassistance.

One of the earliest patient interfaces for providing CPAP treatment wasconstructed to include a fibreglass model of the patient's nose. Themodel was adhered to the patient's nose each night and removed eachmorning. An advantage of this patient interface included the customisedfit, which assisted in a good seal between the patient interface and thepatient's airways. However, the use of adhesive to secure the mask wasinconvenient and not desirable.

Another suitable patient interface is described in U.S. Pat. No.5,243,971 (Sullivan and Bruderer, assigned to the University of Sydney),entitled “Nasal Mask for CPAP having Ballooning/Moulding Seal withWearer's Nose and Facial Contours”. This patent describes a nasal maskwith a soft face-contacting portion, and a rigid shell. The mask is heldin position using headgear. The headgear is attached to the mask andpasses around the back of the wearer's head. The patent depicts two setsof straps in the headgear. The first set comprised a pair of strapspassing from the forehead region to the back of the head. The second setcomprised a pair of straps passing from the nasal region of the mask tothe back of the head.

Another known patient interface is the MIRAGE® nasal mask (by ResMedLtd). This nasal mask includes a pair of headgear attachment points inthe nasal region of the mask shell and a forehead support that includesanother pair of headgear attachment points. The headgear includes asingle piece of a soft, flexible composite fabric with a generallytriangular back portion and four straps. The four straps include a pairof upper straps and a pair of lower straps connecting to the headgearattachment points on the forehead support and nasal mask shellrespectively. At the end of each strap is secured a piece of hookmaterial, which, in use, passes through a headgear attachment point andfastens on corresponding loop material on the strap. The generallytriangular back portion engages the skull in the region of the occiput.The fabric stretches under a load. The base of the triangle ispositioned near and generally in line with the upper straps. Each strapis approximately 2 cm wide and approximately 3 mm thick. The fabric is acomposite of three layers. The inner layer, closest to the patient'shead, is made from nylon. The middle layer is made from neoprene. Theouter layer is made from loop material, suitable for engaging with hookfastening material such as Velcro™. The upper straps have an approximatelength of 19 cm, from the end to the closest corner of the triangle,whilst the lower straps have an approximate length of 26 cm. Includingthe triangle, the upper and lower straps each have an approximate totallength of 60.5 cm. The triangular back portion is an approximateisosceles triangle, with a base of approximately 13.5 cm and sides ofapproximately 9 cm.

Some patients open their mouths during sleep, which means that they maynot receive the benefit of CPAP due to mouth leaks. Various solutionshave been proposed for this problem. One solution is taught in U.S. Pat.No. 6,123,082 (Berthon-Jones, assigned to ResMed Limited), whereby thelips are held closed. Another solution is to use a mask that covers boththe nose and mouth of the patient. An example of a mouth and nasal maskis described in U.S. Pat. No. 5,560,354 (Berthon-Jones, Calluaud, Lynch& Hely, assigned to ResMed Limited).

Another suitable mask system is the MIRAGE® full-face mask (by assigneeResMed Limited). The MIRAGE® full-face mask and headgear is illustratedin FIGS. 1, 2 and 3. Suitable headgear (102) for this mask (100) isconstructed from a composite material of nylon, neoprene and loopmaterial. The headgear similarly comprises a pair of upper (104) and apair of lower straps (106) and a generally triangular back portion(108). The upper strap has a total length of approximately 610 mm asshown in FIG. 3. The straps have an approximate width of 25 mm, however,the upper strap has an approximate width of 19 mm. The triangular regionhas a base of approximately 15.5 cm and two equal sides of approximately11 cm. The upper and lower straps are approximately 192 mm apart. Inaddition, the headgear includes a quick release mechanism (110), asdescribed in the pending U.S. patent application Ser. No. 09/482,718(Lithgow, assigned to ResMed Limited). The quick release mechanismprovides a “rip-chord” that can be pulled upon to separate the headgearand remove the mask in an emergency. When the headgear is positioned onthe patient's head, the quick-release mechanism is situated at the backof the head and the chord runs through loops towards the front of themask system.

Patient interface arrangements include nasal masks, nose and mouthmasks, nasal prongs and nasal pillows. In all forms of patient interfaceused with CPAP for treating sleep disordered breathing, there is a needto counterbalance the force of the pressurised air and to correctlyposition the interface. Since the patient must sleep with thisinterface, it is important that it be comfortable. From themanufacturing and distribution channel perspectives, it is advantageousif one size of headgear fits a large range of head shapes and sizes.

It should be noted that while there are many mask and headgeararrangements available for ventilators, respirators, aviator masks andother breathing apparatus, in general, these may not be suitable for usein the treatment of sleep disordered breathing because they are notsufficiently comfortable to allow the patient to sleep.

The present invention is directed towards providing headgear for holdingand securing a mask for use in the treatment of sleep disorderedbreathing which improves patient comfort, is long lasting and fits awide range of head shapes and sizes.

BRIEF SUMMARY OF THE INVENTION

The invention provides headgear for securing and positioning a masksuitable for the treatment of sleep disordered breathing with thefollowing advantageous combination of features:

-   (i) Constructed from a composite including polyurethane foam-   (ii) Relatively narrow strap ends,-   (iii) Displaced lower strap,-   (iv) A quick release mechanism near the front of the face; and-   (v) Additional attached components to alter the elasticity and    stiffness of the straps.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front three-quarter view of a MIRAGE® full-face mask andprior art headgear system in position on a patient's head.

FIG. 2 shows a rear three-quarter view of a MIRAGE® full-face mask andprior art headgear system on a patient's head.

FIG. 3 shows a view of prior art full-face mask headgear laid flat.

FIG. 4 shows a view of headgear according to an embodiment of thepresent invention.

FIG. 5 shows a view of the quick release mechanism according to thepresent invention.

FIG. 6 shows a view of mask headgear straps in accordance with thepresent invention laid flat.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides headgear (10) for securing and positioning a masksuitable for the treatment of sleep disordered breathing.

(i) Material

The headgear is constructed from a composite of polyurethane foam, loopmaterial and hook material whose shape includes a pair of upper straps(20) and lower straps (30) and a generally triangular back portion (40).A piece of hook material (22) is attached to the end of each of the fourstraps so that the straps may be secured to the attachment points on themask. The end includes a main body (23) and a tapered free end portion(25).

The composite has three layers. The first layer, which in use ispositioned against the head of the patient, is constructed frompolyester or nylon fabric. The second, middle layer is constructed froman hypoallergenic breathable polyurethane foam. The third layer isconstructed from loop material. A suitable material for constructing thecomposite is BREATH-O-PRENE® manufactured by ACCUMED, New York, UnitedStates of America. The total thickness of the composite is approximately2 mm. The upper and lower pairs of straps are approximately 150 mm apartwhen laid flat. The upper and lower straps have an approximate totallength (from the left side to the right side) of 610 mm.

The generally triangular back portion (40) of the headgear (10) isconstructed and arranged to engage generally with the occiput of thepatient's head in use. In use, the base of the triangle is positioned atthe crown of the head, while the apex of the triangle lies generallyjust above the point of contact between the skull and the muscles of theneck.

(ii) Relatively Narrow Strap Ends

The headgear of the present invention is configured to minimize thediscomfort associated with the use of hook material. In prior artheadgear, that discomfort can arise where the hook material may be incontact with the patient's skin, say the cheek or neck regions, forextended periods of time. That undesirable contact will occur where thehook material, to some extent is not entirely located on the receivingloop material, but lies tangential to the loop material, and to someextent extends beyond the loop material and comes in contact with thepatient's skin, either continuously while the headgear is in use or whenit is compressed against the skin, as can occur when the patient headchanges position during the sleep period.

As shown in FIG. 4, the width of each lower strap is constant forapproximately half their length, forming a relatively wide portion (24),and then over a relatively short distance, changes to a narrower widthfor the remaining half of their length, forming a relatively narrowportion (26), terminating at the point where the hook material (22) isjoined to the composite material. A characteristic of this configurationis that the point of contact where the hook material detachably bindswith the strap loop material is positioned on the wide portion (24) andis wider by approximately 1 cm than the width of the engaging hookmaterial. By adopting this configuration, the target region for bindingis relatively greater in area than is the case with prior art. Prior artheadgear includes a tapered end hook section that is of narrower widththan that of the intended contact loop section of the strap. However,the prior art hook section tapered end is less than one half the lengthof the hook section, that is, it does not represent the majority of thelength of the hook section nor does its length represent the majority ofthe length of the intended corresponding contact loop section (i.e., themaximum extent of the loop section covered by the hook section).

In contrast to the prior art, with the present invention the attachmentof the hook material is facilitated, as relatively less precision isrequired in the placement of the hook section to achieve binding. Thisreduced dependence on precision is of advantage to all persons using theheadgear and is of particular benefit to the user that may be trying tofit the headgear in a home environment and where it is not possible todirectly sight the headgear components they are manipulating.Furthermore, compared to the prior art (where the hook material and thetarget region are of substantially the same width), this configurationreduces the chance of exposing some of the hook material to interferewith the wearer, causing discomfort and possibly skin irritation orabrasion.

(iii) Displaced Lower Strap

A length of each of the left and right lower straps is displacedvertically lower by approximately 1 cm (28). By adopting thisconfiguration, it is possible to optimize the design of the base of theback portion so as to achieve the desired security of attachment butavoid compromising comfort in a situation where the lowest point of theheadgear in the occiput region is extended to a position that is lowerthan is otherwise required in order to achieve a sufficiently loweststrap point. This approach avoids the prior art problem of having theheadgear rear portion extending beyond what would otherwise be requiredand thereby engaging the sensitive area below the occipital lobe.

(iv) Quick Release Mechanism

Preferably the headgear of the present invention includes a quickrelease mechanism (50) (see FIG. 5), and this is especially so when theheadgear is intended to be used with a mask that covers the patient'snose and mouth.

The quick-release mechanism (50) suitable for incorporation into thepreferred embodiment is constructed from a sub-assembly of threecomponents: (i) a release loop of a cord material (52), (ii) a generallyrectangular length of hook material (54), and (iii) a generallyrectangular length of a composite fabric (56) which can bind to the hookmaterial, as discussed above. The sub-assembly is generally rectangularin shape and in use forms an extension of one of the lower straps.Preferably the loop cord is constructed from braided cord about 17 cmlong. The cord loop (52) is sewn to one end of the length of hookmaterial (54). The hook material (54) and composite fabric (56) arejoined at the other end of the hook material (54), preferably via a weldjoint. In use, the end of the hook material (54), to which is connectedthe loop cord (52), is secured, using the hook and loop mechanism, tothe end of a modified lower strap which, in contrast to the lower straps(30) shown in FIG. 4, does not contain hook material. The other end (56)of the quick release mechanism (50) is free to be connected to aheadgear attachment point on the mask shell and releasably attached toan exposed portion of the hook material (54). If it is desired to usethe quick-release mechanism (50), it is convenient for the patient topull down on the loop of braided cord (52), thereby disengaging thelower strap from the mask shell and allowing the mask to then be readilyremoved from the patient's face. A quick-release mechanism of thisconfiguration may be used on headgear that is fabricated of materialsand in configurations that are different to those of the type describedabove and as such is an invention in its own right.

(v) Altering the Stiffness and Extensibility

In one form of the invention, the extensibility of the straps can bealtered by attaching lengths of generally inextensible material (62)such as cotton or silk to the straps, as shown in FIG. 6 b. The effectof this arrangement is to make the headgear less extensible along thelength of the straps than in a vertical direction. In a preferredembodiment, lengths of cotton are sewn to the straps.

In another form of the invention, the stiffness of the straps can bealtered by attaching stiffening material (64) to the top and bottom edgeof the straps, as shown in FIG. 6 a. Alternatively, or in addition, thestrap may be stiffened by any other suitable means including by addingstitching as lines, in a crisscross pattern, or both. This makes theheadgear less “floppy” and more convenient to put on the head of awearer.

In another form of the invention, the headgear is constructed from ananisotropic material that is more extensible in a first direction thanin a direction at an angle of 90 degrees to the first direction. Thisenables the headgear to be cut from a single piece of composite materialand yet have different extensibilities in different directions.Preferably, the headgear will be more extensible in a vertical directionthan in a horizontal direction. Hence the upper and lower straps will beless extensible in a direction along their length than in a directionalong their width. This means that the back portion of the headgear canbe more extensible in a direction from the base of the skull to thecrown, than in a direction at right angles to that direction.

1. A headgear for securing and positioning a mask suitable for thetreatment of sleep disordered breathing, comprising: a back portion; apair of elongated upper straps connected to the back portion on opposingsides of the back portion and extending away from the back portion, theupper straps having attachment portions positioned at free ends thereoffor attaching to the mask; and a pair of elongated lower strapsconnected to the back portion below the upper straps on opposing sidesof the back portion and extending away from the back portion, the lowerstraps having attachment portions positioned at free ends thereof forattaching to the mask; wherein a portion of each strap adjacent the backportion and extending approximately half a length of the strap has afirst width and the attachment portion of each strap has a second widthsubstantially narrower than the first width, and wherein in use eachlower strap angles downward from the back portion at a position near theback portion to displace a length of each lower strap, outboard from theangled portion, downward with respect to the back portion.
 2. Theheadgear of claim 1, wherein the displaced length of each lower strap isgenerally horizontal.
 3. The headgear of claim 1, wherein at least oneof the straps is constructed of an extensible material and a generallyinextensible material is attached to that strap to make the strapgenerally inextensible in a direction of its length.
 4. The headgear ofclaim 3, wherein the headgear is formed of a composite having a firstlayer, to be positioned against the head of the patient, constructedfrom a polyester or nylon fabric, a second, middle layer constructedfrom an hypoallergenic breathable polyurethane foam and a third layerconstructed from loop material adapted to engage and attach to a hookmaterial.
 5. The headgear of claim 4, wherein the composite has a totalthickness of approximately 2 mm.
 6. The headgear of claim 1, wherein, atleast one of the straps is constructed of an anisotropic material suchthat the strap is generally inextensible in a direction along its lengthand extensible in a direction along its width.
 7. The headgear of claim1, wherein the second width is narrower than the first width byapproximately 1 cm.
 8. The headgear of claim 1, wherein the second widthis narrower than the first width by at least 1 cm.
 9. The headgear ofclaim 1, wherein the upper straps and the lower straps consistessentially of four straps.
 10. The headgear of claim 9, wherein theupper straps and the lower straps are all substantially parallel to oneanother.
 11. The headgear of claim 9, wherein each of the strapsincludes a hook material portion with a main body located at or near thefree end, and a relatively wider loop material portion positionedbetween the respective free end and the back portion.
 12. The headgearof claim 11, wherein a width of the loop material portion varies along alength of each of the upper and lower straps.
 13. The headgear of claim11, wherein a first width of the loop material portion oriented towardsthe main body of the hook material portion is less than a second widthof the loop material portion oriented towards the back portion.
 14. Theheadgear of claim 9, wherein a distance between the upper straps and thelower straps is approximately 150 mm.
 15. The headgear of claim 14,wherein a length of the upper straps and the lower straps isapproximately 610 mm.
 16. The headgear of claim 1, wherein the upperstraps are positioned above a patient's ears and extend between thepatient's eyes and ears in use, and the lower straps are positionedbelow a patients ears in use.
 17. A headgear for securing andpositioning a mask suitable for the treatment of sleep disorderedbreathing, comprising: a back portion; a pair of elongated upper strapsconnected to the back portion on opposing sides of the back portion andextending away from the back portion, the upper straps having attachmentportions positioned at free ends thereof for attaching to the mask; anda pair of elongated lower straps connected to the back portion below theupper straps on opposing sides of the back portion and extending awayfrom the back portion, the lower straps having attachment portionspositioned at free ends thereof for attaching to the mask; wherein inuse each lower strap angles downward from the back portion at a positionnear the back portion to displace a length of each lower strap, outboardfrom the angled portion, downward with respect to the back portion, anda portion of each lower strap, outboard from the angled portion, islower than a lowest portion of a central region of the back portion. 18.The headgear of claim 17, wherein the displaced length of each lowerstrap is generally horizontal.
 19. The headgear of claim 17, wherein atleast one of the straps is constructed of an extensible material and agenerally inextensible material is attached to that strap to make thestrap generally inextensible in a direction of its length.
 20. Theheadgear of claim 19, wherein the headgear is formed of a compositehaving a first layer, to be positioned against the head of the patient,constructed from a polyester or nylon fabric, a second, middle layerconstructed from an hypoallergenic breathable polyurethane foam and athird layer constructed from loop material adapted to engage and attachto a hook material.
 21. The headgear of claim 20, wherein the compositehas a total thickness of approximately 2 mm.
 22. The headgear of claim21, wherein a length of the upper straps and the lower straps isapproximately 610 mm.
 23. The headgear of claim 22, wherein a distancebetween the upper straps and the lower straps is approximately 150 mm.24. The headgear of claim 17, wherein, at least one of the straps isconstructed of an anisotropic material such that the strap is generallyinextensible in a direction along its length and extensible in adirection along its width.
 25. The headgear of claim 17, wherein thelength of each lower strap outboard from the angled portion is displaceddownward with respect to the back portion by approximately 1 cm.
 26. Theheadgear of claim 17, wherein the length of each lower strap outboardfrom the angled portion is displaced downward with respect to the backportion by at least 1 cm.
 27. The headgear of claim 17, wherein theupper straps and the lower straps consist essentially of four straps.28. The headgear of claim 27, wherein the upper straps and the lowerstraps are all substantially parallel to one another.
 29. The headgearof claim 28, wherein the upper straps are positioned above a patient'sears and extend between the patient's eyes and ears in use, and thelower straps are positioned below a patients ears in use.
 30. Theheadgear of claim 29, wherein each of the straps includes a hookmaterial portion with a main body located at or near the free end, and arelatively wider loop material portion positioned between the respectivefree end and the back portion.
 31. The headgear of claim 30, wherein awidth of the loop material portion varies along a length of each of theupper and lower straps.
 32. The headgear of claim 30, wherein a firstwidth of the loop material portion oriented towards the main body of thehook material portion is less than a second width of the loop materialportion oriented towards the back portion.
 33. A mask, comprising: aframe supporting a soft face-contacting portion, the frame having afirst pair of attachment points and a second pair of attachment points;and the headgear of claim 32, wherein the pair of upper straps isadapted to be coupled to the first pair of attachment points and thepair of lower straps is adapted to be coupled to the second pair ofattachment points.
 34. A headgear for securing and positioning a masksuitable for the treatment of sleep disordered breathing, comprising: aback portion arranged to engage with an occiput of a patient's head inuse a pair of elongated upper straps and a pair of elongated lowerstraps each connected to the back portion and adapted for attaching tothe mask, each of the straps including a first portion positionedadjacent to the back portion and a second portion extending from thefirst portion to an end of each strap; wherein the headgear is formed ofa composite having a first layer, to be positioned against the head ofthe patient, constructed from a polyester or nylon fabric, a second,middle layer constructed from an hypoallergenic breathable polyurethanefoam and a third layer constructed from loop material adapted to engageand attach to a hook material, and each lower strap angles downward todisplace a length of the first portion of each lower strap downward withrespect to the back portion, and the second portion of each strapincludes a lower side displaced upward from a lower side of the firstportion.
 35. The headgear of claim 34, wherein at least one of thestraps is constructed of an extensible material and a generallyinextensible material is attached to that strap to make the strapgenerally inextensible in a direction of its length.
 36. The headgear ofclaim 34, wherein at least one of the straps is constructed of ananisotropic material such that the strap is generally inextensible in adirection along its length and extensible in a direction along itswidth.
 37. The headgear of claim 34, wherein the upper straps and thelower straps consist essentially of four straps.
 38. The headgear ofclaim 37, wherein the upper straps and the lower straps are allsubstantially parallel to one another.
 39. The headgear of claim 38,wherein the upper straps are positioned above a patient's ears andextend between the patient's eyes and ears in use, and the lower strapsare positioned below a patients ears in use.
 40. The headgear of claim39, wherein each of the straps includes a hook material portion with amain body located at or near a free end, and a relatively wider loopmaterial portion positioned between the respective free end and the backportion.
 41. The headgear of claim 40, wherein a width of the loopmaterial portion varies along a length of each of the upper and lowerstraps.
 42. The headgear of claim 40, wherein a first width of the loopmaterial portion oriented towards the main body of the hook materialportion is less than a second width of the loop material portionoriented towards the back portion.
 43. The headgear of claim 38, whereinthe composite has a total thickness of approximately 2 mm.
 44. Theheadgear of claim 43, wherein a distance between the upper straps andthe lower straps is approximately 150 mm.
 45. The headgear of claim 44,wherein a length of the upper straps and the lower straps isapproximately 610 mm.
 46. A mask, comprising: a frame supporting a softface-contacting portion, the frame having a first pair of attachmentpoints and a second pair of attachment points, both adjacent to the softface-contacting portion; and the headgear of claim 44, wherein the pairof upper straps is adapted to be coupled to the first pair of attachmentpoints and the pair of lower straps is adapted to be coupled to thesecond pair of attachment points.
 47. A headgear for securing andpositioning a mask suitable for the treatment of sleep disorderedbreathing, comprising: a back portion having an opening to receive anocciput of a patient's head; and a pair of elongated first strapsconnected to the back portion on opposing sides of the back portion andextending away from the back portion; each first strap having a loopportion positioned along an external surface of its length and a hookportion at a free end thereof for releasably attaching to the loopportion to attach the strap to the mask; wherein a width of the pair offirst straps along the loop portion to which the hook portion releasablyattaches is sufficiently wider than the hook portion that when the hookportion is attached to the loop portion, in use the strap shields auser's face from contact with the hook portion, wherein a width of theloop portion varies along a length of the first pair of straps, andwherein each first strap angles downward to displace downward a lengthof each first strap with respect to the back portion.
 48. The headgearof claim 47, wherein the width of the pair of first straps along theloop portion to which the hook portion releasably attaches is wider thanthe hook portion by approximately 1 cm.
 49. The headgear of claim 47,further comprising a pair of elongated second straps connected to theback portion on opposing sides of the back portion and extending awayfrom the back portion, each second strap having a loop portionpositioned along an external surface of its length and a hook portion ata free end thereof for releasably attaching to the loop portion toattach the second straps to the mask.
 50. The headgear of claim 49,wherein at least one of the straps is constructed of an extensiblematerial and a generally inextensible material is attached to that strapto make the strap generally inextensible in a direction of its length.51. The headgear of claim 49, wherein, at least one of the straps isconstructed of an anisotropic material such that the strap is generallyinextensible in a direction along its length and extensible in adirection along its width.
 52. The headgear of claim 49, wherein thepair of first and second straps consist essentially of four straps. 53.The headgear of claim 52, wherein the pair of first straps and the pairof second straps are all substantially parallel to one another.
 54. Theheadgear of claim 53, wherein the pair of first straps are positionedabove a patient's ears and extend between the patient's eyes and ears inuse, and the pair of second straps are positioned below a patients earsin use.
 55. The headgear of claim 49, wherein a width of the loopportion varies along a length of each of the first and second pairs ofstraps.
 56. The headgear of claim 49, wherein a first width of the loopportion oriented towards the hook portion is less than a second width ofthe loop portion oriented towards the back portion.
 57. The headgear ofclaim 49, wherein the loop portion of each first strap includes a narrowportion extending from the hook portion towards the back portion and awide portion extending from the narrow portion towards the back portion,and includes a transition region between the narrow portion and the wideportion, the transition region including a ramped or tapered portion.58. The headgear of claim 49, wherein a distance between the first pairof straps and the second pair of straps is approximately 150 mm.
 59. Theheadgear of claim 58, wherein a length of the first pair of straps andthe second pair of straps is approximately 610 mm.
 60. The headgear ofclaim 59, wherein the composite has a total thickness of approximately 2mm.
 61. The headgear of claim 49, wherein the headgear is formed of acomposite having a first layer, to be positioned against the head of thepatient, constructed from a polyester or nylon fabric, a second, middlelayer constructed from an hypoallergenic breathable polyurethane foamand a third layer constructed from a loop material adapted to engage andattach to a hook material.
 62. A mask, comprising: a frame supporting asoft face-contacting portion, the frame having a first pair ofattachment points adjacent to the soft face-contacting portion; and theheadgear of claim 47, wherein the first pair of straps is adapted to becoupled to the first pair of attachment points.
 63. A mask, comprising:a frame supporting a soft face-contacting portion, the frame having afirst pair of attachment points and a second pair of attachment points,both adjacent to the soft face-contacting portion; and the headgear ofclaim 1, wherein the pair of upper straps is adapted to be coupled tothe first pair of attachment points and the pair of lower straps isadapted to be coupled to the second pair of attachment points.
 64. Aheadgear for securing and positioning a mask suitable for the treatmentof sleep disordered breathing, comprising: a back portion arranged toengage with an occiput of a patient's head in use, the back portionincluding a top portion, a bottom portion, and a pair of side portions,the pair of side portions converging towards one another as the pair ofside portions extend between the top portion and the bottom portion; apair of elongated upper straps extending from the back portion onopposing sides of the back portion and extending away from the backportion, each of the upper straps having a first portion with a loopmaterial portion between the back portion and a second portion, thesecond portion including a hook material portion, and a main body and atapered free end for attaching to the mask; and a pair of elongatedlower straps extending from the back portion below the upper straps onopposing sides of the back portion and extending away from the backportion, each of the lower straps having a first portion with a loopmaterial portion between the back portion and a second portion, thesecond portion including a hook material portion, and a main body and atapered free end for attaching to the mask, wherein the first portion ofeach strap has a first width, and the second portion of each strap has asecond width narrower than the first width, each lower strap anglesdownward to displace downward a length of the first portion of eachlower strap with respect to the bottom portion of the back portion, eachlower strap angles upward from a lower side of the first portion todisplace upward the second portion with respect to the first portion,the pair of upper straps and the pair of lower straps are allsubstantially parallel to each other, and the downward displacement ofthe first portion of each lower strap forms a wider portion to which thehook material portion attaches.
 65. The headgear of claim 64, wherein alower side of the bottom portion of the back portion includes a cutoutportion formed between the downward angled lower strap on each side ofthe back portion.
 66. The headgear of claim 65, wherein the sideportions are in general alignment with the cutout portion.
 67. Theheadgear of claim 64, wherein at least one of the straps is constructedof a substantially extensible material and a generally inextensiblematerial is attached to that strap to make the strap generallyinextensible in a direction of its length.
 68. The headgear of claim 64,wherein, at least one of the straps is constructed of an anisotropicmaterial such that the strap is generally inextensible in a directionalong its length and generally extensible in a direction along itswidth.
 69. The headgear of claim 64, wherein the upper straps and thelower straps consist essentially of four straps.
 70. The headgear ofclaim 69, wherein the upper straps are positioned above a patient's earsand extend between the patient's eyes and ears in use, and the lowerstraps are positioned below a patients ears in use.
 71. The headgear ofclaim 70, wherein a width of the loop material portion varies along alength of each of the upper and lower straps.
 72. The headgear of claim70, wherein a first width of the loop material portion oriented towardsthe main body of the hook material portion is less than a second widthof the loop material portion oriented towards the back portion.
 73. Theheadgear of claim 64, wherein a distance between the upper straps andthe lower straps is approximately 150 mm.
 74. The headgear of claim 73,wherein a length of the upper straps and the lower straps isapproximately 610 mm.
 75. The headgear of claim 64, wherein the topportion and pair of side portions of the back portion form an open spacehaving a generally triangular shape.
 76. The headgear of claim 75,wherein a base of the triangular shape is positioned in use at a crownof the user's head, and an apex of the triangular shape of the backportion is positioned in use just above a point of contact between askull and muscles of the user's neck.
 77. The headgear of claim 64,wherein the headgear is formed of a composite having a first layer, tobe positioned against the head of the patient, constructed from apolyester or nylon fabric, a second, middle layer constructed from anhypoallergenic breathable polyurethane foam and a third layerconstructed from loop material adapted to engage and attach to a hookmaterial.
 78. The headgear of claim 77, wherein the composite has atotal thickness of approximately 2 mm.
 79. A mask, comprising: a framesupporting a soft face-contacting portion, the frame having a first pairof attachment points and a second pair of attachment points, bothadjacent to the soft face-contacting portion; and the headgear of claim64, wherein the pair of upper straps is adapted to be coupled to thefirst pair of attachment points and the pair of lower straps is adaptedto be coupled to the second pair of attachment points.
 80. A headgearfor securing and positioning a mask suitable for the treatment of sleepdisordered breathing, comprising: a back portion; a pair of upper strapsextending from the back portion on opposing sides of the back portion,the upper straps having attachment portions for attaching to the mask; apair of lower straps extending from the back portion on opposing sidesof the back portion, the lower straps having attachment portions forattaching to the mask; wherein the pair of upper straps and the pair oflower straps consist essentially of four straps, the four straps are allsubstantially parallel to one another, and each lower strap in useincludes a downwardly angled portion to displace a length of each lowerstrap, outboard from the angled portion, downward with respect to theback portion.
 81. The headgear of claim 80, wherein the upper straps arepositioned above a patient's ears and extend between the patient's eyesand ears in use, and the lower straps are positioned below a patientsears in use.
 82. The headgear of claim 80, wherein at least one of thestraps is constructed of a generally extensible material and a generallyinextensible material is attached to that strap to make the strapgenerally inextensible in a direction of its length.
 83. The headgear ofclaim 80, wherein, at least one of the straps is constructed of ananisotropic material such that the strap is generally inextensible in adirection along its length and extensible in a direction along itswidth.
 84. The headgear of claim 80, wherein the headgear is formed of acomposite having a first layer, to be positioned against the head of thepatient, constructed from a polyester or nylon fabric, a second, middlelayer constructed from an hypoallergenic breathable polyurethane foamand a third layer constructed from loop material adapted to engage andattach to a hook material.
 85. The headgear of claim 80, wherein thecomposite has a total thickness of approximately 2 mm.
 86. A mask,comprising: a frame supporting a soft face-contacting portion, the framehaving a first pair of attachment points and a second pair of attachmentpoints, both adjacent to the soft face-contacting portion; and theheadgear of claim 80, wherein the pair of upper straps is adapted to becoupled to the first pair of attachment points and the pair of lowerstraps is adapted to be coupled to the second pair of attachment points.87. A headgear for securing and positioning a mask suitable fortreatment of sleep disordered breathing, consisting essentially of: aback portion, and four substantially parallel straps extending from theback portion, the four straps including a pair of upper straps extendingfrom opposed lateral sides of the back portion, and a pair of lowerstraps positioned below the upper straps and extending from the backportion, each said strap including a hook material portion and a loopmaterial portion extending between the hook material portion and theback portion, each loop material portion includes a first loop portiondefining an enlarged width target region for the hook material portion,and a second loop portion extending between the target region and thehook material portion, said second loop portion having a width that isless than a width of the target region, and each first loop portion ofthe lower straps has a lower edge displaced downward relative to a loweredge of back portion while maintaining substantial parallelism betweenthe four straps.
 88. The headgear of claim 87, wherein a length of theupper straps, including a top portion of the back portion, isapproximately equal to a length of the lower straps, including a bottomportion of the back portion.
 89. The headgear of claim 88, wherein thefirst loop portion extends over approximately over half a length of thestrap, and the second loop portion extends over approximately half thelength of the strap.
 90. The headgear of claim 88, wherein the first andsecond loop portions are of approximately equal length.
 91. The headgearof claim 87, wherein each hook material portion includes a main bodyhaving a width generally equal to a width of the second loop portion.92. The headgear of claim 87, further comprising a first transitionregion between the first loop portion and the second loop portion, saidfirst transition region including a ramped or tapered portion.
 93. Theheadgear of claim 92, wherein each strap includes a second transitionregion angled downward from the back portion, between the lower edge ofthe back portion and the lower edge of the first loop portion.
 94. Theheadgear of claim 93, wherein a distance between the first transitionregion of the lower straps and the respective hook material portion isdifferent than a distance between the second transition region of theupper straps and the respective hook material portion.
 95. The headgearof claim 94, wherein a distance between the first transition region ofthe lower straps and the respective hook material portion is greaterthan a distance between the second transition region of the upper strapsand the respective hook material portion.
 96. The headgear of claim 95,wherein the back portion includes a top portion, a bottom portion and anintermediate portion connecting the top and bottom portions, theintermediate portion including a pair of straps that converge towardsone another in a direction from the top portion to the bottom portion.97. The headgear of claim 96, wherein the top portion of theintermediate portion is positioned at the crown of the patient's head inuse, while a lower section of the intermediate portion lies generallyjust above the point of contact between the skull and muscles of theneck in use.
 98. The headgear of claim 97, wherein the top portion andthe pair of straps define a generally triangular shape.
 99. The headgearof claim 98, wherein the upper straps are positioned above a patient'sears and extend between the patient's eyes and ears in use, and thelower straps are positioned below a patients ears in use.
 100. Theheadgear of claim 99, wherein the headgear is formed of a compositehaving a first layer, to be positioned against the head of the patient,a second, middle layer of foam and a third layer constructed from saidloop material portion.
 101. The headgear of claim 100, wherein thecomposite has a total thickness of approximately 2 mm.
 102. A mask fordelivery of pressurized gas in the range of 3-30 cmH₂O to a patient, themask comprising: a frame supporting a soft face-contacting portion, theframe having a first pair of attachment points and a second pair ofattachment points, and the headgear of claim 87, wherein the pair ofupper straps is adapted to be coupled to the first pair of attachmentpoints and the pair of lower straps is adapted to be coupled to thesecond pair of attachment points.